My mom taught me as a child, it’s really hard to unyell once you’ve yelled. If you want to get what you want, start soft. You can always yell once that fails, but you once you’ve yelled, it’s too late for the soft approach.

Robert Cialdini’s book Influence discusses several “Weapons of Inflence”. This first part examines the power of reciprocation — our need to give back to someone who has given something to us — and how this is used to influence us every day in our buying decisions and in other areas. Parts 2 and 3 will look at social proof and comment and consistency.